Dental instrument



gk. M. WITHYCOMBE 2 1,723,226

DENTAL INSTRUMENT Filed March 31, 1925 Patented Aug. 6, 1929.

Um'rizn STATES ROBERT MORSE WITHYCOIVIBE, OF SYDNEY, I'vIE'lV SOUTH WALES. AUSTRALIA.

DENTAL INSTEUIIIENIE.

Application filed March 31, 1925. Serial No. 191157.

This ii'ivcnlio'si relates to dental instruments and particularly to operative tools such as curettes, lu'oacl'ies and the like, having a common handle into which a plurality of tools may be intercham cably and selectively secured, and the invention has for principal object the promotion of conven ience and sanitation i n the use of such instruments by avoiding the need oil. mechanical coupling dcv" is between the tool. and handle, such as screw-threads, clamps, chucks, etc. by substituting therefor a cementitious comlmsitien oil matter initially associated with e .ier the handle or tool, and which l at all times actively antiseptic and of such. character as to be readily and. repeatedly rendered plastic and adhesive when it is (lesired to insert or remove the tool relatively to the handle, but normally rigid at temperatures up to and including the boiling point of water, forming a ri id bond between the tool and handle, and permitting the instrninent or its parts to be sterilized by boiling, without deteriorating said bond.

Another object of the invention the provision oil an improved operating tool bendable by the operator at any desired angle, and in a definite plane and so constructed as automatically to determinethat point in the length of the tool at which the bending shall take place.

Other objects of the invention will appear the following description oi? an illustrative embodiment thereof nroceeds.

In the drawings Figure 1 is a longitudinal view partly in section showing a form of my invention.

Figure 2 is a similar view taken at right angles to the position shown in Figure 1.

l igure 3 is a longitudinal view of a portion of one of the dental instruments showing the working end bent at the weakened point.

Referring now in detail to the several iigr,

Fate/ht lf h). 1,598,668, granted Scartmnlicr 7, 1920. v

i iorse metal contains, as one of its essential ingredients a compound of copper which is inhewintly antiseptic, oxide of copper being considcrml as an example of such inedient. Among the physical charzarteris of h'lorse metal which adn') it particularly for the uses of the presentinvention are the facility with which may be melted at relatively low 'ttlllPOlzllilHOFi, its tenacity ot adherence to metallic surlaces, when melted, its normal hardness and rigidity at ordinary ten'iperalures, up to and above the boiling point of water, and its immunity :i'rom material deterioration through. repeated melting; ij'iiilCt} there may be other substances hating these (pialities in common with. h [orse metal, the invention is not to be considered as limited to Morse metal for the particular cementitious material employed.

In manu acturing the tool according to my invention, the shank is dipped, into molten Morse metal, said shank preferably having been heated beforehand to approximately the same temperature as the metal. It is then withdrawn from the mass of mo].- ten metal and permitted to cool, retaining a coating 4, as shown. It is within the scope of the invention to apply the hilorse metal or its equivalent, altermitivcly to the interior of the socket instead of to the shank.

In using' my in'iproved dental instrument, the preferred technique is for the operator, after selecting a suitable tool to hold the socketed end of the handle in a flame until it has been heated above the melting, point oi. Morse metal. The tool with the coated end is then troduced into the socket, the ll torso metalbecoming liquefied so as to completely till the interstico between the shank and socket, adherinc intin'iately to the wall of the latter, and upon cooling, uniting the tool and handle in a unitary bond. The joint thus termed is actively antiseptic, and tree from any crack or crevice into which contaminated matter may lodge.

\Vhen the operator desires to change the tool he reheats the handle until the Morse metal has again liquefied, at which time the tool may readily be withdrawn from the handle. some of the Morse metal may adhere to the walls of the socket, and some to the shank in. the act of separation, but

Cir

Morse metal.

ordin care 15 exercised in heating the tool or han .le when applying or so mating the parts of the instruir t, the lt'lorse metal will not be burned and can withstand the heating operation repeatedly without deterioration.

Aside from furnishing a truly ant-L septic coupling means between the tool and handle, the invention a'llords a quick and convenient means for selectively changing one tool for another while a dental operation is in progress and it necessitates the provision of but onehandle for a number oi? tools from which the selection may be made.

The tool portion of the instrument preterably provided with a knite-tempered "orking end 5, the shank or an intermediate portion thereof being left bendable as indicated at 6. By this means the do t is enabled to bend the working end or the l larly with respect the shank to suitsituations in which the tool is to he used thereby making a single tool 'rulii the tunetion many tools. The shank is preferably weakened in the untempered portion by diminishing its thickness, as shown. at 7, in Figures 2 and 3, so that the bending will always take place the weal-(erred point in a definite plane and at a predetermined distance from the end of the shank which. engages the handle so that the working length of the shank of the instrument at all times practically uniform. The tempered part of the shank retains its rectilinear form which is of great advantage in a dental tool, atl ording a sighting means for the guidance of the operator, and also transmitting to best advantage the manipulative moven'ient of the tool.

It is possible with this feature of the invention, for the dentist to have one hand occupied at the mouth of the patient, and at the same time with the other hand to bend the instrument by pressing the working end thereof aga'. any unyieldingsurface such as his mixing pallet with the certainty of the bend occurring in a definite point, in a definite plane, and without deforming the rectilinear disposition of the portion of the tool below the bend.

The shank may be weakened by forming concave depressions in one or both sides oi? the shank so that the bending of the working end of the tool will always take place in the same plane.

While l have illustrated and described what I believe to be a practical embodiment of: my invention, it is to be understood that the invention is broad enough to include surgical instruments, generally, in its hold of application and that changes may be made from time to time in the specific form and relation of the several parts, usage may require without departing from the spirit and scope of the invention as defined by the appended claims.

Having described my invention what I claim as new and desire to secure by Letters Patent, is

l. A rental instrument comprising a separable handle and tool therefor, one of said parts being provided with a socket, and the other part havinga portion telescoping within said socket, and a cementitious substance of anti-septic character previously separately associated with and hardened on one oi said parts and adapted when suitably temperature treated to make a unitary antiseptic joint between said parts when in telescoped relation.

2. A dental instrument comprising a separable handl and tool, one of said parts being provided with a socket and the other part having; a portion telescoping within said socket, and a cementitious substance of anti-septic character previously separately associated with and hardened on one of said parts and adapted when suitably temperature treated to'make a unitary joint between said portions when in telescoped relation, said substance being normally hard and rigid at temperatures up to and including the boiling point of water but fluid at a higher rano'e o1 temperature.

3. A dental tool having a tempered working end, and a bendable untempcred portion, the latter being mechanically weakened at a definite pointand in a definite plane.

In testimony whereof I have hereunto set my hand.

ROBERT MORSE lVITI-IYCOMBE.

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